The CRF and XR 200 got redesigned cases to fit a wider transmission, so they have a stronger, wider gear set; they don't use the same cases as standard 5-speed cases.
The only one that might work is the XL/XR125 from the early 80s. I've heard that they fit into the standard CB 5-speed cases. It is a kickstart transmission though, so the gears are probably narrower/weaker than your 5-speed, which was even a problem in the (redesigned) 6-speed in the XR200.
There's also a possibility of the NX125 transmission working, though there are differences between the JD09 and JD12. I have a JD12 and have been trying to get case dimensions to determine the same sort of stuff, but it seems like Honda did a one-off case design for the NX, it has some funky aspects to it that don't match up with the rest of the family.
If you look, I have a thread on here about transmissions, I'm trying to gather data, and I'd appreciate your contribution.
I honestly think for you, the easiest solution would be the CRF230 motor, as a counterbalancer will interfere with the standard engine mounts.
I'd recommend giving this a read:
https://www.xrv.org.uk/forums/attach...xr200-mods.pdf